Autonomous vehicles, for instance, vehicles that do not require a human driver, can be used to aid in the transport of passengers or items from one location to another. Such vehicles may operate in a fully autonomous mode where passengers may provide some initial input, such as a pickup or destination location, and the vehicle maneuvers itself to that location.
When a person (or user) wants to be physically transported between two locations via a vehicle, they may use any number of transportation services. To date, these services typically involve a human driver who is given dispatch instructions to a location to pick up the user. In many cases, the human driver and the user are able to arrange an exact location for the user to be picked up. In addition, drivers and users are able to “flag down” one another, use eye contact, speak to one another, or other signals to indicate recognition of one another and thereby agree to some location prior to the vehicle reaching the exact location for the pickup or drop off. This is not readily achievable in the case of autonomous vehicles which do not have a human driver.